If your PlayStation 4 is only recording the first 15 minutes of gameplay in a session, which would mean if you’re an hour into your game session and you saw something you wanted to share it wouldn’t be there. This is a fix from Sony support for the problem. It has worked for at least one person.
Documents You Should Read Before:
-Turn off the PS4 and wait until the light turns off.
-Hold down the power button until you hear two beeps. The first beep you hear when you press the button and another beep 7 seconds later.
-Connect your controller and press the PS Button then choose the option that says Rebuild Database.
-It says that it will take a few hours but it really won’t.
Once that is done you should be able to get on the main menu and every feature of the PS4 including Share should would perfectly.